Protein kinases are a large group of intracellular and transmembrane signaling proteins in eukaryotic cells (for example, see Manning, G., D. B. Whyte, et al. (2002). “The protein kinase complement of the human genome.” Science 298(5600): 1912-1934). These enzymes are responsible for transfer of the terminal (gamma) phosphate from ATP to specific amino acid residues of target proteins. Phosphorylation of specific amino-acid residues of target proteins can modulate their activity leading to profound changes in cellular signaling and metabolism. Kinases can be found in the cell membrane, cytosol and organelles such as the nucleus and are responsible for mediating multiple cellular functions including metabolism, cellular growth and division, cellular signaling, modulation of immune responses, and apoptosis. Cell surface receptors with protein tyrosine kinase activity are known as receptor tyrosine kinases. This large family of proteins includes growth factor receptors with diverse biological activity (for example, see Lemmon, M. A. and J. Schlessinger (2010). “Cell signaling by receptor tyrosine kinases.” Cell 141(7): 1117-1134).
Aberrant activation or excessive expression of various protein kinases are implicated in the mechanism of multiple diseases and disorders characterized by benign and malignant proliferation, excess angiogenesis, as well as diseases resulting from inappropriate activation of the immune system. Thus, inhibitors of select kinases or kinase families are expected to be useful in the treatment of diseases and disorders such as: cancer, arthritis, myeloproliferative disorders, cardiac hypertrophy, lung fibrosis, hepatic fibrosis, atherosclerosis, restenosis, glomerulonephritis, psoriasis, lupus, multiple sclerosis, macular degeneration, asthma, reactive synoviotides and the like (for example, see: Chitu, V. and E. R. Stanley (2006). “Colony-stimulating factor-1 in immunity and inflammation.” Curr Opin Immunol 18(1): 39-48; Mitchell-Jordan, S. A., T. Holopainen, et al. (2008). “Loss of Bmx nonreceptor tyrosine kinase prevents pressure overload-induced cardiac hypertrophy.” Circ Res 103(12): 1359-1362; Uemura, Y., H. Ohno, et al. (2008). “The selective M-CSF receptor tyrosine kinase inhibitor Ki20227 suppresses experimental autoimmune encephalomyelitis.” J Neuroimmunol 195(1-2): 73-80; Cohen, P. (2009). “Targeting protein kinases for the development of anti-inflammatory drugs.” Curr Opin Cell Biol 21(2): 317-324; Menke, J., W. A. Rabacal, et al. (2009). “Circulating CSF-1 promotes monocyte and macrophage phenotypes that enhance lupus nephritis.” J Am Soc Nephrol 20(12): 2581-2592; Grimminger, F., R. T. Schermuly, et al. (2010). “Targeting non-malignant disorders with tyrosine kinase inhibitors.” Nat Rev Drug Discov 9(12): 956-970; Hilgendorf, I., S. Eisele, et al. (2011). “The oral spleen tyrosine kinase inhibitor fostamatinib attenuates inflammation and atherogenesis in low-density lipoprotein receptor-deficient mice.” Arterioscler Thromb Vasc Biol 31(9): 1991-1999; Sharma, P. S., R. Sharma, et al. (2011). “VEGF/VEGFR pathway inhibitors as anti-angiogenic agents: present and future.” Curr Cancer Drug Targets 11(5): 624-653; Fabbro, D., S. W. Cowan-Jacob, et al. (2012). “Targeting cancer with small-molecular-weight kinase inhibitors.” Methods Mol Biol 795: 1-34).
Examples of kinases that can be targeted to modulate disease include receptor tyrosine kinases such as members of the platelet-derived growth factor receptor (PDGFR) and vascular endothelial growth factor receptor (VEGFR) families.
The PDGFR family of receptor tyrosine kinases includes cFMS (CSF-1R) and FMS-like tyrosine kinase 3 (FLT3) which normally regulate cellular function through activation by external ligands.
cFMS is a transmembrane receptor kinase that binds to colony-stimulating-factor-1 (CSF-1) and interleukin (IL)-34 (IL-34) (for example, see Chihara, T., S. Suzu, et al. (2010). “IL-34 and M-CSF share the receptor Fms but are not identical in biological activity and signal activation.” Cell Death Differ 17(12): 1917-1927) and which plays an important role in macrophage, monocyte and osteoclast biology. The cFMS-CSF-1 pathway is upregulated in various human diseases that involve chronic macrophage activation. Activation of cFMS plays a central role in arthritis through its role in differentiation of monocytes (for example, see Paniagua, R. T., A. Chang, et al. (2010). “c-Fms-mediated differentiation and priming of monocyte lineage cells play a central role in autoimmune arthritis.” Arthritis Res Ther 12(1): R32) and inhibition of cFMS has been shown to be effective in pre-clinical models of arthritis (for example, see: Conway, J. G., H. Pink, et al. (2008). “Effects of the cFMS kinase inhibitor 5-(3-methoxy-4-((4-methoxybenzyl)oxy)benzyl)pyrimidine-2,4-diamine (GW2580) in normal and arthritic rats.” J Pharmacol Exp Ther 326(1): 41-50); Ohno, H., Y. Uemura, et al. (2008). “The orally-active and selective c-Fms tyrosine kinase inhibitor Ki20227 inhibits disease progression in a collagen-induced arthritis mouse model.” Eur J Immunol 38(1): 283-291; Huang, H., D. A. Hutta, et al. (2009). “Pyrido[2,3-d]pyrimidin-5-ones: a novel class of antiinflammatory macrophage colony-stimulating factor-1 receptor inhibitors.” J Med Chem 52(4): 1081-1099; and Illig, C. R., C. L. Manthey, et al. (2011). “Optimization of a potent class of arylamide colony-stimulating factor-1 receptor inhibitors leading to anti-inflammatory clinical candidate 4-cyano-N-[2-(1-cyclohexen-1-yl)-4-[1-[(dimethylamino)acetyl]-4-piperidinyl]phenyl]-1H-imidazole-2-carboxamide (JNJ-28312141).” J Med Chem 54(22): 7860-7883) suggesting that cFMS kinase inhibitors may be useful in treatment of human arthritis. cFMS inhibition has also been shown to be effective in a pre-clinical model of multiple sclerosis (Uemura, Y., H. Ohno, et al. (2008). “The selective M-CSF receptor tyrosine kinase inhibitor Ki20227 suppresses experimental autoimmune encephalomyelitis.” J Neuroimmunol 195(1-2): 73-80).
Inhibitors of cFMS are expected to be therapeutically useful in treatment of tenosynovial gain cell tumor, pigmented villonodular synovitis and other reactive synovitides which are often characterized by high levels of CSF-1 expression (for example, see Cupp, J. S., M. A. Miller, et al. (2007). “Translocation and expression of CSF1 in pigmented villonodular synovitis, tenosynovial giant cell tumor, rheumatoid arthritis and other reactive synovitides.” Am J Surg Pathol 31(6): 970-976). Preclinical studies using antibodies targeting CSF-1 predict that cFMS inhibitors may be useful in treating these human diseases (Cheng, H., P. W. Clarkson, et al. (2010). “Therapeutic Antibodies Targeting CSF1 Impede Macrophage Recruitment in a Xenograft Model of Tenosynovial Giant Cell Tumor.” Sarcoma 2010: 174528).
cFMS is important in osteoclast differentiation and function and therefore cFMS inhibition may be useful in modulating osteoclast function in arthritis as well as in the formation and progression of bone metastases (for example, see Manthey, C. L., D. L. Johnson, et al. (2009). “JNJ-28312141, a novel orally active colony-stimulating factor-1 receptor/FMS-related receptor tyrosine kinase-3 receptor tyrosine kinase inhibitor with potential utility in solid tumors, bone metastases, and acute myeloid leukemia.” Mol Cancer Ther 8(11): 3151-3161). Secretion of growth factors and immunosuppressive cytokines by tumor-associated macrophages suggests that targeting their function through inhibition of cFMS could be a useful anti-cancer therapy (for example, see Bingle, L., N. J. Brown, et al. (2002). “The role of tumour-associated macrophages in tumour progression: implications for new anticancer therapies.” J Pathol 196(3): 254-265). Accordingly, cFMS inhibition or knockdown has shown efficacy in tumor models through inhibition of tumor associated macrophage (for example, see Aharinejad, S., P. Paulus, et al. (2004). “Colony-stimulating factor-1 blockade by antisense oligonucleotides and small interfering RNAs suppresses growth of human mammary tumor xenografts in mice.” Cancer Res 64(15): 5378-5384; and Manthey, Johnson et al. 2009) suggesting that cFMS inhibitors may have utility in the treatment of human cancer.
FLT3 is mutated in approximately 30% of adult patients with acute myeloid leukemia (AML) and has a significant impact on prognosis (for example, see Gilliland, D. G. and J. D. Griffin (2002). “The roles of FLT3 in hematopoiesis and leukemia.” Blood 100(5): 1532-1542). Accordingly, inhibition of FLT3 is expected to be useful in the treatment of malignancies such as AML (for example, see: Knapper, S. (2011). “The clinical development of FLT3 inhibitors in acute myeloid leukemia.” Expert Opin Investig Drugs 20(10): 1377-1395; Pemmaraju, N., H. Kantarjian, et al. (2011). “FLT3 inhibitors in the treatment of acute myeloid leukemia: the start of an era?” Cancer 117(15): 3293-3304). Additionally, FLT3-ligand is implicated in induction and progression of arthritis suggesting that inhibitors of FLT3 may be useful in the treatment of arthritis (for example, see Dehlin, M., M. Bokarewa, et al. (2008). “Intra-articular fms-like tyrosine kinase 3 ligand expression is a driving force in induction and progression of arthritis.” PLoS One 3(11): e3633).
Inhibition of members of the vascular endothelial growth factor (VEGF) and TIE2 families are expected to have anti-angiogenic effects which may be useful in the treatment of many diseases or disorders including cancer and arthritis (for example, see: Timar, J. and B. Dome (2008). “Antiangiogenic drugs and tyrosine kinases.” Anticancer Agents Med Chem 8(5): 462-469; Huang, H., A. Bhat, et al. (2010). “Targeting the ANGPT-TIE2 pathway in malignancy.” Nat Rev Cancer 10(8): 575-585; and Huang, H., J. Y. Lai, et al. (2011). “Specifically targeting angiopoietin-2 inhibits angiogenesis, Tie2-expressing monocyte infiltration, and tumor growth.” Clin Cancer Res 17(5): 1001-1011).
Fibroblast growth factor receptor 1 (FGFR1) provides a further example of a kinase that may be targeted for therapeutic effect. FGFR1 is amplified in select subsets of cancers (for example, see: Courjal, F., M. Cuny, et al. (1997). “Mapping of DNA amplifications at 15 chromosomal localizations in 1875 breast tumors: definition of phenotypic groups.” Cancer Res 57(19): 4360-4367; and Tsujimoto, H., H. Sugihara, et al. (1997). “Amplification of growth factor receptor genes and DNA ploidy pattern in the progression of gastric cancer.” Virchows Arch 431(6): 383-389) and inhibition of FGFR1 has shown efficacy in preclinical models of cancer (for example, see Gozgit, J. M., M. J. Wong, et al. (2012). “Ponatinib (AP24534), a multi-targeted pan-FGFR inhibitor with activity in multiple FGFR-amplified or mutated cancer models.” Mol Cancer Ther. 11(3):690-9).
Inhibition of kinases using small molecule inhibitors has successfully led to several approved therapeutic agents used in the treatment of human conditions. Herein, we disclose a novel family of kinase inhibitors. Further, we demonstrate that modifications in compound substitution can influence kinase selectivity and therefore the biological function of that agent and disease state for which it may be useful as a therapeutic agent.